27" Imac Screen switched off constantly

[D.P.]

I have a late 2011 27" Imac running OSX 10.10.5 Yosemite that keeps switching the screen off. The computer is running in the background and I can revive is with CTRL+SHIFT+Eject. But typically a few minutes later it switches off.
Temperatures don't seem abnormal to me?

However, putting the screen on the lowest brightness helps prolong sessions but makes it impossible to see. So I thing it would be temperature form the screen but its a bit pathetic that it doesn't have sufficient cooling to run the screen properly.

This has been a persistent problem for years. I have taken it to the mac store twice and they have never fixed it.


If it is a cooling problem how can I increase fan-speeds? It has plenty of airflow sitting on top of the desk.

 

[Journey]

It's the inverter board that has a fault. You'll need to replace it, or try and convince Apple that the same fault existed since you bought it.

The inverter controls the backlight of the panel btw.

Edit: Can you see the picture at all when it goes off, you might need to get very close to the screen or shine a light through the front of it.

 

[D.P.]

It's the inverter board that has a fault. You'll need to replace it, or try and convince Apple that the same fault existed since you bought it.

The inverter controls the backlight of the panel btw.

Edit: Can you see the picture at all when it goes off, you might need to get very close to the screen or shine a light through the front of it.

Thanks, I've not seen an image, it appears entirely black but I will see what i can see next time. At the very least you have given me a very liekly candidate that I had no idea about before. I searched and see many people having the problem of the screen turning off but no one seemed to offer a firm answer.

 

[D.P.]

Just cranked the brightness back to normal levels and the screen went black within a minute. Had a look and couldn't see anything but form some google research found I need to use a strong torch in order to detect anything. Sure enough I could see the screen was working.

Ok, so now I need to see if I want to repair it myself or get Apple to do

 

[Journey]

It's not a difficult repair by any means, and the are plenty of guides online showing the process end to end. I'd get a quote from Apple to see how much they want, but it will probably be five fold more expensive then doing it yourself.